A 57-year-old man has been arrested and questioned on suspicion of murdering a woman who was found dead in Bassingbourn eight years ago.

Diane Stewart (not pictured) was the former wife of Ian Stewart, who was given a life sentence for murdering author Helen Bailey at their Royston home. Picture: Alice Boagey

Detectives from the Bedfordshire, Cambridgeshire and Hertfordshire Major Crime Unit arrested the man, of Bedford, on Tuesday following the re-examination of the death of 47-year-old Diane Stewart. The 57-year-old has since been released under investigation.

Ms Stewart – whose former husband Ian Stewart is currently serving a life sentence in prison for killing his fiancée, Royston author Helen Bailey, in 2016 – was found dead at her home in Bassingbourn on June 25, 2010.

The cesspit police excavated at Ian Stewart's Royston home, where they found Helen Bailey's body and that of her dog Boris. Picture: Herts police

At the time Ms Stewart’s death was found to have been of natural causes, after an epileptic fit.

Following her death, Ian Stewart joined a forum for widows and widowers, and the forum’s Facebook group, which Ms Bailey had also joined after her husband John Sinfield died in Barbados in 2011.

Helen Bailey with her miniature dachshund Boris, whose body was found in a cesspit along with hers at their Royston home. Picture: Herts police

During the 2017 murder trial, where Stewart was sentenced to a minimum of 34 years in prison after killing 52-year-old Ms Bailey and dumping her in a cesspit beneath their home alongside her beloved dog Boris, he said Ms Bailey had messaged first and they eventually got together through their shared grief.

In the wake of Stewart’s sentencing on February 23, 2017, DCI Jerome Kent – who led the murder investigation – said that he would also be heading a probe into the death of Stewart’s former wife Diane, who he had two sons with.